Bipolar plate and battery

Abstract

The bipolar plate comprises a plate body, a plurality of flow channels are formed in the plate surface of the plate body, each flow channel is provided with an inlet and an outlet, and the inlet and the outlet of each flow channel are formed in the side wall of the plate body in the thickness direction; the flow channel is of a Tesla valve structure so as to accelerate the flowing speed of the active material in the flow channel. According to the technical scheme, in the charging or discharging process of the battery, the active substance flows in the flow channel, and the flow channel forms the Tesla valve structure, so that the active substance has smaller pressure drop loss in the flowing process in the flow channel, the flowing speed of the active substance in the flow channel can be accelerated, and the service life of the battery is prolonged. Therefore, the charging and discharging rate of the battery is improved, the problem of concentration polarization of active substances at different positions in the battery can be solved, and the active substances can better and more fully intrude into the electrode and are uniformly distributed in the electrode.

Description

Technical Field

[0001] The present disclosure relates to the technical field of batteries, and specifically, to a bipolar plate and a battery. Background Art

[0002] Currently, traditional bipolar plates generally adopt a flat plate structure, and active substances are transported through porous carbon electrodes (such as carbon felts). This structure has a large flow resistance, seriously affecting the mass transfer ability of the flow battery, the uniformity of the distribution of active substances in the electrode, and is not conducive to improving the charge and discharge rate of the battery. Summary of the Invention

[0003] The purpose of the present disclosure is to provide a bipolar plate and a battery to improve the charge and discharge rate of the battery.

[0004] To achieve the above purpose, a first aspect of the present disclosure provides a bipolar plate, including a plate body, on the plate surface of the plate body, a plurality of flow channels are formed, each flow channel has an inlet and an outlet, and the inlet and outlet of each flow channel are both formed on the side wall in the thickness direction of the plate body;

[0005] The flow channel is formed into a Tesla valve structure to accelerate the flow rate of active substances in the flow channel.

[0006] Optionally, the flow channel includes a plurality of interconnected conduction units, each conduction unit includes an arc-shaped groove and a straight groove, both ends of the arc-shaped groove in its length direction are first open ends, both ends of the straight groove in its length direction are formed as second open ends, one of the first open ends of the arc-shaped groove is connected to one of the second open ends of the straight groove, and the other first open end of the arc-shaped groove is connected to the other second open end of the straight groove.

[0007] Optionally, the width of the arc-shaped groove is 2 mm to 3 mm;

[0008] The width of the straight groove is 2 mm to 3 mm.

[0009] Optionally, the plate body has two opposite plate surfaces, and the flow channels are formed on each plate surface.

[0010] Optionally, along the length direction or width direction of the plate surface, the plurality of flow channels are arranged at intervals, and the distance between every two adjacent flow channels among the plurality of flow channels is equal.

[0011] Optionally, the flow channel extends linearly on the plate surface.

[0012] Optionally, the flow channel extends in a serpentine shape on the plate surface.

[0013] Optionally, the distance between two adjacent ones of the flow channels is 1 mm to 2 mm.

[0014] Optionally, the depth of the flow channel is 1 mm to 2 mm.

[0015] The second aspect of the present disclosure provides a battery, including the bipolar plate as described above.

[0016] Through the above technical solution, during the charging or discharging process of the battery, the active material flows in the flow channel, and since the flow channel is formed into a Tesla valve structure, this Tesla valve structure can utilize the spatial structure to promote the flow of the active material, accelerate the active material through the physical structure, and reduce the energy loss of the active material during transportation. That is to say, during the process of the active material flowing in the flow channel, there is a smaller pressure drop loss. Therefore, the flow rate of the active material in the flow channel can be increased, thereby improving the charging and discharging rate of the battery.

[0017] Moreover, precisely because the active material has a smaller pressure drop and a faster flow rate in the above flow channel, it can ensure that the concentrations of the active material at the inlet end and the outlet end of the flow channel are as close as possible, that is, it can solve the problem of concentration polarization of the active material at different positions in the battery, enabling the active material to better and more fully penetrate into the electrode and be evenly distributed within the electrode.

[0018] Other features and advantages of the present disclosure will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification, and are used together with the following specific implementation to explain the present disclosure, but do not constitute a limitation to the present disclosure. In the drawings:

[0020] Figure 1 is a top view schematic diagram of a bipolar plate provided by an exemplary embodiment of the present disclosure;

[0021] Figure 2 is Figure 1 an enlarged schematic diagram of part A of

[0022] Figure 3 is a schematic cross-sectional view of a bipolar plate provided by an exemplary embodiment of the present disclosure, in which flow channels are formed on both surfaces of the bipolar plate, and the flow channels located on different surfaces are arranged opposite to each other in the thickness direction of the plate body;

[0023] Figure 4 is a schematic cross-sectional view of a bipolar plate provided by another exemplary embodiment of the present disclosure, in which flow channels are formed on both surfaces of the bipolar plate, and the flow channels located on different surfaces are arranged staggeredly in the thickness direction of the plate body.

[0024] Description of Reference Numerals

[0025] 1- bipolar plate; 2- plate body; 20- flow channel; 21- inlet; 22- outlet; 23- conduction unit; 231- arc groove; 232- straight groove. DETAILED DESCRIPTION

[0026] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0027] In the present disclosure, unless otherwise stated, the directional words used are only for the convenience of describing the present disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, and a specific directional structure and operation. Therefore, they cannot be understood as a limitation of the present disclosure. The terms "inside" and "outside" refer to the inside and outside of the corresponding structural contour.

[0028] In addition, it should be noted that the terms used, such as "first" and "second", are used to distinguish one element from another and do not have order or importance. In addition, in the description with reference to the drawings, the same reference numerals in different drawings represent the same elements.

[0029] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified or limited, the terms "disposed," "connected," "connected," and "installed" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; and they may refer to direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this disclosure based on specific circumstances.

[0030] refer to Figures 1 to 2 As shown, the first aspect of the present disclosure provides a bipolar plate 1, including a plate body 2, with a plurality of flow channels 20 formed on the plate surface of the plate body 2, each flow channel 20 having an inlet 21 and an outlet 22, and the inlet 21 and outlet 22 of each flow channel 20 are formed on the side wall in the thickness direction of the plate body 2; the flow channel 20 is formed into a Tesla valve structure to accelerate the flow speed of the active material in the flow channel 20.

[0031] Through the above technical solution, during the charging or discharging process of the battery, the active material flows in the flow channel 20. And since the flow channel 20 is formed into a Tesla valve structure, this Tesla valve structure can utilize the spatial structure to promote the flow of the active material, accelerate the active material through the physical structure, and reduce the energy loss of the active material during transportation. That is to say, during the process of the active material flowing in the flow channel 20, it has a smaller pressure drop loss. At the same time, the above Tesla valve structure can also accelerate the flow rate of the active material in the flow channel 20, thereby improving the charging and discharging rate of the battery.

[0032] Moreover, precisely because the active material has a smaller pressure drop in the above flow channel 20 and can be continuously accelerated during the flowing process, it is possible to avoid the problem of the flow rate attenuation of the active material during the flowing process in the flow channel 20, and ensure that the concentrations of the active material at the inlet 21 end and the outlet 22 end of the flow channel 20 are as close as possible, that is, the active material flows at the same or nearly the same speed in the front section, middle section, and rear section of the flow channel 20, which can solve the problem of concentration polarization of the active material at different positions in the battery, and enable the active material to better and more fully penetrate into the electrode and be evenly distributed in the electrode.

[0033] Optionally, as Figures 1 to 2 shown, the flow channel 20 may include a plurality of interconnected conduction units 23. Each conduction unit 23 includes an arc-shaped groove 231 and a straight groove 232. Both ends of the arc-shaped groove 231 in its length direction are first open ends, and both ends of the straight groove 232 in its length direction are formed as second open ends. One first open end of the arc-shaped groove 231 is connected to one second open end of the straight groove 232, and the other first open end of the arc-shaped groove 231 is connected to the other second open end of the straight groove 232. In this way, during the process of the active material flowing in the flow channel 20, the active material can bypass all the arc-shaped grooves 231 and then flow unobstructedly from the inlet 21 to the outlet 22, and obtain an accelerating effect due to the flow pressure, thereby realizing the acceleration of the active material.

[0034] Theoretically speaking, the more the number of the arc-shaped grooves 231 and the straight grooves 232 in the flow channel 20 per unit length, the more obvious the accelerating effect on the active material. In this way, the number of the arc-shaped grooves 231 and the straight grooves 232 that match the requirements can be set according to the demand for the charging and discharging rate of the battery.

[0035] Optionally, in an exemplary embodiment provided by the present disclosure, the width of the above arc-shaped groove 231 may be 2 mm to 3 mm; the width of the straight groove 232 is 2 mm to 3 mm. On the one hand, the arc-shaped groove 231 and the straight groove 232 can meet the requirements of the residence time, flow rate, and uniformity of the active material in the flow channel 20 under the above dimensions. On the other hand, it can reduce the processing difficulty, thereby reducing the processing cost.

[0036] Optionally, in order to further improve the charge and discharge rate of the bipolar plate 1, in the present disclosure, the plate body 2 has two plate surfaces arranged away from each other, flow channels 20 can be formed on each plate surface, and each flow channel 20 is formed into a Tesla valve structure. In this way, when the bipolar plate 1 works, the flow channels 20 on different plate surfaces of the plate body 2 can all supply the active material to flow, thereby increasing the flow rate of the active material and improving the output or input efficiency of charge.

[0037] In order to further improve the charge and discharge efficiency of the bipolar plate 1, in the present disclosure, optionally, as Figures 1 to 2 shown, along the length direction or the width direction of the plate surface, a plurality of flow channels 20 can be arranged at intervals, and the distance between every two adjacent flow channels 20 among the plurality of flow channels 20 is equal. In this way, the active material can flow in different flow channels 20 on different plate surfaces, thereby improving the charge and discharge efficiency of the bipolar plate 1. Moreover, since the distance between every two adjacent flow channels 20 among the plurality of flow channels 20 is equal, in this way, it can be ensured that the active material is more uniformly distributed at different positions of the plate body 2, thereby reducing or avoiding the problem of concentration polarization of the active material to improve the battery performance.

[0038] Here, it should be noted that the present disclosure does not limit the specific arrangement form and shape of the above-mentioned flow channels 20 on the plate surface of the plate body 2. For example, in an exemplary embodiment provided by the present disclosure, as Figures 1 to 2 shown, optionally, the flow channels 20 can extend linearly on the plate surface. The flow channels 20 extending linearly on the plate body 2 are more convenient for processing the flow channels 20 and can effectively reduce the processing cost.

[0039] Alternatively, in another exemplary embodiment provided by the present disclosure, optionally, the flow channels 20 can also extend in a serpentine shape on the plate surface. The flow channels 20 extending in a serpentine shape can cover a larger area on the plate body 2 and are more conducive to the uniform distribution of the active material at different positions on the plate surface.

[0040] Optionally, in an embodiment provided by the present disclosure, the distance between two adjacent flow channels 20 can be 1 mm to 2 mm. At this size, it can not only meet the requirements of the concentration and dispersion degree of the active material on the plate body 2, but also facilitate the processing and forming of the flow channels 20 and reduce the processing cost.

[0041] In an embodiment provided by the present disclosure, the above-mentioned plate body 2 can be made of a graphite plate with a thickness of 3 mm to 5 mm. The graphite plate can play the following roles:

[0042] The graphite plate can provide a sufficient reaction surface on its surface to enhance the electrochemical reaction and improve the efficiency and performance of the battery;

[0043] Provide an electron transfer channel: The graphite plate is an electron transfer channel in the electrochemical reaction, which can transfer electrons to the electrolyte through conductivity to achieve the battery reaction;

[0044] Enhance corrosion resistance: The graphite plate has good corrosion resistance, can resist corrosion in the electrochemical reaction, and extend the service life of the battery;

[0045] Improve battery performance: By changing its porosity, specific surface area, conductivity and other characteristics, the graphite plate can improve the battery performance and can be customized according to specific application scenarios.

[0046] In addition, the conductivity of the above-mentioned graphite plate should be greater than 300 s / cm and the resistivity should be less than 3.3 mΩ·cm.

[0047] As described above, precisely because the plate body 2 is made of a graphite plate with a thickness of 3 mm to 5 mm, in the embodiment where flow channels 20 are formed on both opposite surfaces of the plate body 2, the depth of the flow channels 20 is 1 mm to 2 mm. In this way, it is possible to avoid the influence of the flow channels 20 formed on one surface on the flow channels 20 on the other surface due to excessive depth, so as to ensure that the flow channels 20 on both surfaces can maintain an independent operating state.

[0048] In the disclosure, along the thickness direction of the plate body 2, as Figure 3 shown, the flow channels 20 provided on the two surfaces can be arranged opposite to each other in the thickness direction of the plate body 2, or, in another embodiment provided by the present disclosure, as Figure 4 shown, the flow channels 20 provided on the two surfaces can also be arranged staggeredly in the thickness direction of the plate body 2. In this way, it can be restricted by the thickness of the plate body as little as possible. The present disclosure does not limit this and can adaptively set and adjust the flow channels 20 according to specific situations.

[0049] The second aspect of the present disclosure provides a battery, including the bipolar plate 1 as above. This battery has all the beneficial effects of the above-mentioned bipolar plate 1, and the present disclosure will not elaborate on this.

[0050] In the present disclosure, the type of the above battery is not limited, that is, the battery can be any battery containing active substances, such as flow batteries, fuel cells, etc.

[0051] The preferred embodiments of the present disclosure have been described in detail above with reference to the drawings. However, the present disclosure is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

[0052] In addition, it should be noted that, in the above specific embodiments, the various specific technical features described can be combined in any suitable manner without conflict. To avoid unnecessary repetition, the present disclosure will not separately describe various possible combination manners.

[0053] Furthermore, any combination can be made among various different embodiments of the present disclosure, as long as it does not violate the idea of the present disclosure, and it should also be regarded as the content disclosed by the present disclosure.

Claims

1. A bipolar plate, characterized in that, It includes a plate body, and a plurality of flow channels are formed on the plate surface of the plate body. Each flow channel has an inlet and an outlet, and the inlets and outlets of each flow channel are both formed on the side walls in the thickness direction of the plate body; The flow channel is formed into a Tesla valve structure to accelerate the flow rate of the active material in the flow channel.

2. The bipolar plate according to claim 1, characterized in that The flow channel includes a plurality of interconnected conduction units. Each conduction unit includes an arc-shaped groove and a straight groove. Both ends of the arc-shaped groove in its length direction are first open ends, and both ends of the straight groove in its length direction are formed as second open ends. One of the first open ends of the arc-shaped groove is connected to one of the second open ends of the straight groove, and the other first open end of the arc-shaped groove is connected to the other second open end of the straight groove.

3. The bipolar plate according to claim 2, wherein The width of the arc-shaped groove is 2 mm to 3 mm; The width of the straight groove is 2 mm to 3 mm.

4. The bipolar plate according to claim 1, wherein The plate body has two opposite plate surfaces, and the flow channels are formed on each of the plate surfaces.

5. The bipolar plate according to any one of claims 1-4, wherein Along the length direction or the width direction of the plate surface, a plurality of flow channels are arranged at intervals, and the distance between every two adjacent flow channels among the plurality of flow channels is equal.

6. The bipolar plate according to claim 5, characterized in that The flow channel extends linearly on the plate surface.

7. The bipolar plate according to claim 5, characterized in that, The flow channel extends in a serpentine shape on the plate surface.

8. The bipolar plate according to any one of claims 1-4, characterized in that, The distance between two adjacent flow channels is 1 mm to 2 mm.

9. The bipolar plate according to any one of claims 1-4, characterized in that, The depth of the flow channel is 1 mm to 2 mm.

10. A battery, characterized in that: It includes the bipolar plate according to any one of claims 1-9.

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